Apparatus for forming tapered tubes



Oct.- 14, 1936.

L. H. BRINKMAN APPARATUS oR FORMING TAPERED TUBES Filed June 24',r 1924@sheets-sheet Oct. 14, 1930. 1 H. BRINKMAN APPARATUS FOR FORMING TAPEREDTUBES Filed June 24, 1924 6 Sheets-Sheet .3

INVENTOR Oct. 14, 1930. L. H. BRINKMAN APPARATUS FOR FORMING TAPEREDTUBES Filed June 24, `1924 6 Sheets-Sheet 4 INVENTOR Oct. 14, 1930.

L. H. BRINKMAN 1,778,181

APPARATUS FOR FORMING TAPERED TUBES 6 Sheets-Sheet 5 Filed June 24, 192gL INVENTOR 0ct. 14, 1930. L. H. BRINKMA 1,773,181

' Y APPARATUS FOR FO'RMING TAPEED TUBES Filed June 24, 1%,2'4 6sheets-sheet 6 lll Il "31. K

` BY /ZvZu-AEQATIORNEY `Patented Oct. 14, 1930 LOUIS H. BRINXMAN, F GLENRIDGE, NEW JERSEY A PPABAZD'IUS FOR FOBMING TAPERED TULBES Applicationled Ju'ne 24,

This invention' relates to the forming of tubes, especially thin tubesof varying diameters, which are adapted for use as the shafts of golfclubs but may be employed in other I uses to which they are adapted; theinvention also relates to the improved golf clubs, `the shafts of whichmay be formed by this invention.

Metal tubes form a light, durable and l0 strong shaft for golf clubs butheretofore it has not been proposed to provide such tubular shafts withwalls of varying thickness or in varying the tube diameter to providethe desired feel of the clubincluding flexibility and strengthdistributed at desired points. Thus it is desirable that the shaftshould be of minimum diameter so as to provide greatest flexibility afew inches from the head of the club and also the end of the shaft whereit joins the head should be larger so as to provide strength in securingto the head and also to loca-te the flexibility in an appropriateposition lengthwise of the shaft. Also in order to properly distributethe strength of the shaft throughout its length the tube wall should bemade of varying thickness. N o such metal tubular shaft for a golf clubhas ever before been provided so far as I am aware and othercharacteristics of golf clubs 359 according to this invention willappear from the appended description in connection with the accompanyingdrawings.

It may, therefore, be said to be an important object of the invention toprovide golf 55 clubs with tubular metal shafts having characteristicsas indicated herein.

v A further object of the invention is to provide apparatus for formingmetal tubes to be used as golf club shafts or in other applica- 4i tionsto which they may be adapted. A further object of the invention is toprovide a method for forming metal tubes as indicated.

Other and ancillary objectsl of the inven- 'tion will appearhereinafter.

In the accompanying drawings which illustrate the invention v Fig. 1 isa side elevation of a machine embodying the invention; 1

Fig. 2 is a longitudinal section on an en- 1924. Serial No. 721,965.

larged scale, partly broken away, of a. portion of the apparatus shownin Fig. 1;

Fig. 3 is a section on the line 3-3 of Fig. 2;

Fig. 4 is a section on the line 4 4 of Fig. 2;

Fig. 5 is a section on the line 5 5 of Fig. 2; 55

Fig. 6 is a longitudinal section partl broken away and some of the partsremove of a machine similar to that shown in Fig. 2 but havinga modifiedform of mandrel.

Fig. 7 isa sectional view, on an enlarged 60 scale, with parts brokenaway and omitted showing a modified form of die and mandrel for use in amachine as shown in Fig. 2;

Fig. 8 is a side elevation of a shaft for a golf club;

Fig. 9 is a view, showing the shaft in section, of a golf club with ashaft as shown in Fig. l0 is a longitudinal section, on an enlargedscale, of a machine as indicated in connection with Fig. 6, but with amodified form of mandrel and die;

Fig. 11 is a view of a golf club showing the shaft in longitudinalsection;

Fig. 12 is a longitudinal section of a modi- 75 fied form of die for usein a machine as shown in Fig. 2 whereby the shaft as shown in Fig.

11 may be made;

Fig. 13 is a longitudinal section ofparts of a die and mandrel showingforms of those devices whereby the shaft formed by the dies and mandrelsof Figs. 12 and 13, may be finished in a machine `of the Character asshown in Fig. 6;

Fig. 14 is a view of a golf club, the shaft 85 being shown in section;

Fig.. 15 is a longitudinal section of a portion of a machine so modifiedfrom that form as shown in Fig. 2 asto be adapted to form the shaft asshown in Fig. 14;

Fig. 16 is a section on the line 16-16 of Fig. 15;

Fig. 17 isa longitudinal sectional view of a machine with parts brokenaway indicat- 95 ing a modified construction of the machine as shown inFig. 6, whereby the shaft as initially manufactured in the machine asshown in Fig. l5 may be finished.

Fig. 18 is a fragmentary view partly in 100 and its cooperating mandrel,with parts broken away, whereby the shaft of Fig. 19 may be finished,this die and mandrel being employed in a machine as shown in Fig.A 6.

Referring to the drawings and first to Figs. 1 to 5 inclusive which showa means for drawing a taperingtube of uniform wall thickness, theapparatus comprises a frame 1 which may be similar to the usual latheframe having a bed 2' similar to the usualw lathe bed upon which slidesthe-tapering die having a frame 3 and engaging with a feed screw 4rotatably mounted in the frame and driven by means of gears 5 .and 6from the pulley wheels 7 driven by a belt 8 adapted to be shippedbetween reversely rotating pulleys on a drive shaft as is a commonexpedient in lathe practice, to reverse the rotation of the feed screw4.

Mounted at one end ofthe frame is a stationary drawhead comprising theframe 9 fixed to the frame by means of lag screws such as 10 and 11.lRotatably mounted in the frame 9 is a chuck member 12 to which issecuredthe end of the tube 13 to be tapered, the end of the tube beingentered within a socket 14 in the chuck member and surrounding a rod 16having; a tapered head 17 engaging inclined ends of the chuck jaws andadapted when drawn to the right (Fig. 2) to force the chuck jawsoutwardly and .grip the tube against the walls of the socket 1.4. Whenthe head is moved in the other direction the pressure on the chuck jawsis relieved andthe tube may be withdrawn. The rod 16 lextends through abushing or sleeve 18 fixed k1n the member 12 and at its end is providedwith a screw-thread 19 with which is engaged a hand wheel 20. It will beseen that the hand wheel 20, coming against the end of the bushing 18,when turned in one direction will expand the chuck jaws 15, and whenturned in the other direction the pressure upon the jaws will berelieved. l; ixed to the chuck member 12 is a driving pulley 21 whichmay be provided with sprocket teeth 22 kfor engagement with the drivingchain or may be a smooth pulley for cooperation with a belt. A rollerbearing 23 between the pulley 21 and the frame 9 takes the thrust uponthe chuck member occasioned by the pull upon the tube being operatedupon Fixed in the frame 9 are nuts 24 and 25 through which respectivelywork the screws 26 and 27 which are rotatably mounted at 28 and 29 inthe frame of the die head. These screws are prevented from slidingendwise with relation to the die head by means of shoulders 30 and 31 onthe screw 26 and 32 and 33 on the screw 27. T he members upon which thescrews 26 and 27 are formed, extending beyond'the die frame 3 areprovided respectively with screw threads 34fand 35 whereby they engagewith `the ball adjusting head 36 which is carried by these screwImembers.l

Rotatably mounted within the head 36 by means of` ball bearings 37 isthe sleeve 38 constituting a cage for the balls 39. The sleeve 38 isprovided with holes as shown in each of lwhich is located a ball. Eachof these holes is of considerably greater diameter than the ball itcontains so that there is considerable clearance about the ball and itmay readily find its own seat without binding. v Preferably thethickness of the ball ca e, at the point where the balls are held, is aout onehalf the diameter of the balls. The balls are enclosed within ahard steel die 4() -secured in the frame 3 by means of a ring 41 screwedinto the frame 3 and thereby the die is secured firmly to that frame.The die is provided with a central recess of circular section, the wallsof such recess against which the balls bear being tapered longitudinallyof the apparatus or otherwise formed to guide the balls to produce thedesired conformation ofthe tub e. rllhus in the apparatus as shown inFig. 2 longitudinal movement of the ball cage 38 whereby the 'balls aremoved over the cylindrical portion 42 ofthe die walls will result iny auniform diameter of the tube whereas a similar movement of the ball cagewhen the balls are in contact with the tapered or inclined wall 43 ofthe die' will cause the balls to be moved inwardly or outwardlyaccording to the direction of movement of `the cage and a correspondingchange'in .the exterior diameter of the tube will be effected.

Within the tube 13 and into the recess of the die extends a mandrel 44which is inl screw- .threaded engagement with a thrust collar 45 4Thelongitudinal thrust upon the -mandrel 44 is takenv by ball bearings 48and 49 between the thrust collar and the yoke 47. This mandrel extendsunder the balls and provides a support for the tube being drawn at thepoint .where it is drawn under the balls and also by occupying adefinite relationship with relation to the interior of the wall of thedie upon which the balls move,. deines the thickness v of the tube. Itwill be apparent that the outsidediameter of the tube under the wallswill be defined Aby Ithe balls, while the inside diamiev eter will bedelined by the kdiameter under the Aballs and the thickness of the tubewill be the mandrel where it extends into the recess.

in the dye is substantially parallel to an element of the die Wallssurrounding the mandrel. The drawn tube is. thus of uniform thicknessbut as the ball cage is moved longitudinally the outside diameter of thetube is varied. In order to lubricate the balls, a suitable lubricantmay be introduced through a pipe 50 from any suitable source of supplyand dropped upon the ball cage along which it will travel to the balls.

I It will be apparent that the taper of the tube will depend upon theinclination of the die faces with which the balls engage and the rate atwhich the ball cage is moved longitudinally relative to the travel ofthe die head.

It will be seen that the ball cage 38 moves back and forth with the balladjusting head yse '35. The last mentioned screws have their threads cutin such direction that as the die head moves to the left the balladjusting head 36 will move to the right (closer to the die head 3) andthe balls will be movedy longitudinally toward the right (Fig. 2). Thethreads 34|and 35 are of such pitch that the balls will be thus movedlongitudinally at the desired speed'with relation to the movement of thedie head.. It is convenient .in many cases for the ball adjusting head36 to move longitudinally with relation to the die head at one-tenth ofthe speed of movement of the die head with'relation to the bed of thelathe.

In operating-the apparatus of Fig. -2 the.

drawhead having been moved to the left by manipulating the'feed screw ordiscngaging the die head from that screw by the use of a split nut,usual in vlathepractice, and the chuck members 15 being loosened bunscrewing the feed wheel 20 and moving t e head 17 to the left', oneend of the tube to be drawn, which may be a tube of uniform diameter orof a taper or other shape lwhich it is desired to modify has one endentered within the die beneath the balls and around the mandrel and isushed to the left until its end may be entered) within the socket '14 ofthe chuck member when it may have its end entered within that socket andclamped in the chuck member by means of the rod 16 and 'hand wheel 20 inthe manner ,as before described.

The drawhead is then moved to the right in proximity to the 'chuck vandthrown into paratus then being set in operation the chuck head will berotated by the wheel 21 and the die head will be carried to the left bythe feed Screw, the ball adjusting head 36 bein moved toward the diehead.y` So long as t e balls remain within the surface 42 there will beno change in the diameter of the tube, but as soon as the balls enterwithin the inclined or conical surface 43 they will be forced inwardlythereby decreasing the diameter of the tube which will continue untilthe end of the tapering operation is reached. The tube, bein fixed inthe drawhead, is drawn between t e balls as through a die orifice and at'all times the tube is supported by the interior, mandrel which definesthe thickness of the tube wall and supports it against collapsing whichis of Great im portance in connection with thin tiibes as the tube isprevented from collapsing under the pressure caused by big reduction.VIt is thus often made possible to affect all the taper desired in thetube by a single draw, and Where the Wall of the tube is comparativelthin and weak as for instance in the manu acture of tubular metal shaftsfor golfclubs.

It will be seen that the tube drawn is lrotated by the rotation of thechuck to which it is secured and thus causes the balls 39 to rotate androll about on the tube and against the die surface thereby working andforging the metal down to the desired form so that it is of superioruality after being drawn.

In thus rotating a out the die the balls carry with them the ball ca e38 which rotates easily upon its ball caring. Also, the mandrel beingrotatably mounted ma turn with the tube so as not to produce bin 'ng orAfriction.

The tapered tube as thus formed may be suitable for many uses withoutfurther treat- `ment but it will be noted that the tube 13in theapparatus of Fi ..2 is subjected, between the action necessar the diehead. 'll strains ldeleterious to some uses of `the tube, this beingespecially true in relation to devices such as the shafts of golf clubs-where it is necessary that the shaft should be straight and truewithout distorting stresses or strams. To accomplished the resultsindicated the tube may be given a further treatment whereby theobjectionable stresses and strains are removed.I This may beaccomplished by takin the tube as taperedl by means of a large re uctionper draw 'in the machine of Fig. 2 and placing it in another machine thesame as Fig. 2 except that there is amandrel within the tube upon whichit is yrolled down. Such mandrel extends the length of the tube rawheadand ie head, to the twisting to turn it, the balls etc. in

,and upon it the metal is vkneaded, breaking up the stresses andstrains, and the mandrel reenforces the tube 'nst the torsional strainso thatwhen. alight reduction of .the

his may develop stresses and` of Figs. 1 to 5 inclusive.

vltube is taken in this manner there will be produced a tube of thedesired taper and free from objectionable stresses and strains.

Thus in Fig. 6 the tube 13 taken from the machine of Fig. 2 is placed inanother machine similar in all particulars except that .the mandrel 51is fixed to the chuck operating head 17 and extends the whole length ofthe tube beneath the balls 39 positioned by means of the ball cage 38within the die 40, all as described in connection with the apparatus'The tube 13 is fixed in the chuck member 12 as previously described sothat when the chuck is rotated the mandrel 51 and tube 13 rotatetogether. The die head having been placed at the right (adjacent thedrawhead,

the die will be moved to the left (Fig. 6)- by the feed screw and thetube will be drawn through the die, a light reduction being given by theballs in a manner as described in con-l formity and accuracy arerequired as in the shafts of golf clubs.

A golf stick shaft as shown in side eleva- `tion in Fig.` 8 and insection in Fig. 9 may be made b the employment of a machine as shown inig. 2 but with a modified form of mandrel as shown in Fig. 7, the diehaving the inclined face 52 and-the cylindrical face 53, the mandrel 44being provided with l corresponding inclined faces 54 and cylindricalportion 55. The operation of the machine as described will then producea tube having a substantially uniform thickness of v wall and taperingthroughout the greater part of its length, but having`a short section atits end of uniform diameter.

thus formed is then placed in a machine the same as Fig. 2 but with themandrel arrangement similar to that' shown in Fig. 6, the specific formof mandrel and die being shown in Fig. 10 wherein the mandrel secured tothe clutch member and extending the full length of the tube to befinished, comprises the tapered portion 56 and the portion L57 ofuniform diameter. The die in which the balls are located has. the ballengaging surfaces comprising the inclined surface 58 of a taper suitableto cause the tube 59 to be rolled down upon the mandrel as the die ismoved along the tube and the balls 39 shifted to the right by means 'ofthe cage 38,`and also the cylin drical surface 58 adapted to guide theballs in rolling the portion 62v of the tube upon the The tubeycylindrical portion of the mandrel. A light rolling' having beenaccomplished upon the full length mandrel, a true and accurate golf clubshaft free from objectionable stress and strains and of a form as shownin side elevation in Fig. 8 and 1n longitudinal section 1n Fig. 9 isproduced. This golf shaft, it will be seen, includes the tapered section56 extending for the greater portion of the length of the shaft to thepoint 61 and thence to the ,end is the section 57 of uniform diameter(the whole shaft being of uniform thickness of wall) adapted to receivethe shank 63 of the head 64 of a golf club, the two being securedtogether in any suitable manner. f

' The golfclub shaft as shown in Fig. 11

having a tapered tube of uniform thickness of wall for the section 65which extends for the greater portion of its length and terminating. atthe narrowest portion 66 and thence having the section 67 of uniforminternal diameter but of increasing external diameter (the tubeincreasing in thickness) to a point 68 whence the tube shaft extendswith uniform thickness of wall and uniform diameter of tube to its end,may be formed with a modified form of die as shown in Fig. 12, the

mandrel being tapered and having a cylindrical end as shown in Fig. 7.In Fig. 12 the die is modified from that shown in Fig. 7 in that Whilethe face 69 is tapered in the same manner as is the face 52, the face ofthe ydie corresponding to 53 of Fig. 7 is formed of the portion 70 whichincreases in diameter from left to right and the section 71 of the facewhich is cylindrical. It will be seen that with this apparatus the tubewill have a wall of uniform thickness (being thatvin the uniformclearance between the balls and` mandrel under the die faoe 69 throughthe section 65). When the inclined section 70 is encountered by theballs they will be permitted to vgradually move radiall outward and, thecorresponding portion o the many drel being cylindrical the tube wallwill become thicker (the inside diameter of the tube remaining the same)so that there will be a taper at the outside wall 'of the tube and uponreaching the face section 71 of the die,

the tube will bemaintained of uniform diam- I eter, but with the thickerwall, to the end of the tube. The tube thus jformed may be placed upon amandrel extending the full length of the tube as indicated in Fig. 13.This mandrel being secured to the tube securing chuck in the drawhead asdescribed in connection with Fig.6 and extending' b'eneath the balls asindicated. This mandrel comprises'the tapered portion 72 extendingthroughout the length- 65 of the shaft and the cylindrical portion 73extending within the section from the point 66 to the end of thetube andthis is then passed through a die 74 in a machine like that shown inFig. 2 but with the modied mandrel arrangement referred to. This die .74 had the inclined portion 75 corresponding to the portion 69 of Fig.12, the inclined portion 76 corresponding to the portion 7 0 of Fig. 12and the cylindrical portion 77 corresponding to the portion 71 of Fig.12. The shaft having been finished upon this last device the finishedarticle is as shown in Fig. 11.

It is to be observed in connection with the shaft of Fig. 11 that thepoint 66 is thatl of the least outside diameter of the tube, the shaftbeing of greater outside diameter upon both sides of that point. Thisaffords a means for decreasing the size of the shaft adjacent the head,or wherever desired so as to give suitable flexibility at desired pointsof the shaft.

In order to produce a shaft as shown in F ig. 14, namely having one ofuniform thickness of wall throughout but having a tapered section 78extending throughout the greater part of its length to a point ofminimum diameter 79 and thence tapering oppositely through a section 80to a point 81 and thence being of cylindrical section 82 to the end ofthe shaft, may be formed by means of a ma` chine now to be described.

Referring to Figs. 15 and 16, the apparatus comprises a diehead 3 anddie, a mandrel 44, a drawhead frame 9, a' rotatable chuck 12 in which issecured the tube 13 to be drawn and the ball adjusting head 36, all asdescribed in connection with the apparatus of Fig. 2 and relatedfigures. The means for shifting the ball adjusting head 36, however, isdiiferent, provision being made for the shifting of the balls inopposite directions, to produce reverse ta ers on the tube being drawn.The means or accomplishing this will now be described.

The rods 83 and 84 rotatably mounted in the die head are provided withscrew threads 34 'and 35 engaging with thedie adjusting head 36'- in thesame manner as described in connect-ion with the apparatus of Fig. 2.These rods, however, are provided at one part with parallel helicalgrooves 85 of low pitch, these grooves being 18()o apart about the rod.These grooves run into another pair of parallel grooves 86, of steeperpitch than the grooves 85, at 87, the grooves 85 and 86 being helicallyformed about the rod so that the rod is substantially right-handedlythreaded byv one pair of grooves and left-handedly threaded by the otherpair.

' It will be seen that each of the grooves of the pair 85 and one of thepair 86 form one continuous groove and within each of these groovesenters an anti-friction' roller 88 rotatably mounted on a stud 89 fixedin the nut or bushing 90 which is itself adjustably xed in the frame 9.Itwill now be seen that as the die head is'moved b the feed screw inrelation to the drawhea the rotatable rods 83 and 84 will be drawnthrough the nuts in grooves is of long pitch and the parts are soproportioned that the balls will be moved to the right against thetapering die face 7 8 to form the taper over the greater length 78 ofthe tube. When the point 79 of minimum diameter has been reached thestuds 89 will have reached the points 87 and, entering uponA the grooves86 will cause the rods 83 and 84 to be turned in the opposite-direction,thereby reversing the turning of the screw threads 34'- and 35 andmoving the ball adjustin die in the other direction, i. e. toward the let in Fig. 15. The inte-rior face of the die now grows larger as theballs are retracted toward the left so that the diameter of the tubeincreases to form the reversely tapering portion` 80, It is to beobserved, however, that the taper 80 involves a given Variation indiameter over a much shorter length of tube than is the case with thepart 78. As has been noted, however, the pitch of the grooves 86 is muchsteeper than that of the grooves 85 so that the retraction of the-balladjusting head toward the left (Fio. 15) is much more rapid than thetravel of the balls toward the right during the tapering of the parts78. Having reached the cylindrical portion 91 of the die face, the ballswill travel toward the left rapidly but with a substantially uniformdiameter of tube so that the part 82 is formed.

This may then be finished by placing it in a machine as shown anddescribed in connection with Fig. 15 but with the long mandrel as shownin Figs. 17 and 18. The'tapered mandrel 92 in those figures is securedto and extends from the chuck to the least diameter 7 9 of the tube andhas screwed into the end of it a rever-sely tapering plug 93substantially corresponding to the tapered portion 80 of the tube. Thisplug has a screwthreaded plug 94 engaging in a tapped hole 95 in themandrel '92 and has a kerf 96 in its end whereby this plug may beunscrewed from the end of the mandrel to permit the tube to be placedonthe mandrel or removed therefrom. The threads on the parts 94 and 95should be of such direction that the tendency during the operation uponthe tube will be to screw up the plug rather than to unscrew it so thatthe plug may not becomey accidentally detached from the mandrel duringthe operation of the machine. The constructlon and movement of the dieand shifting of the balls in reverse directions to follow the desiredform of the tube is the same as described and shown in connection withFig. 15. In fact the machines may be the same except for the differencein mandrels as indicated.

It is sometimes advantageousthat, a golf thickened at the waist orportion of least diameter so that while flexibility of the shaft isobtained at that point the club shaft may be strengthened. The club asshown in Fig. 19 comprises the portion 110 having a long taper, the wallof the tube being of substantially uniform diameter throughout thegreater portion of its length. This portion 110 extends to the waist 97whence the revervsely tapered portion 98 extends to the substantiallycylindrical portion 99 joined to the head 100 of the club. It will beobserved that the wall of the tube is thickened at 97, the wall thentapering in both directions to a thinner wall which obtains throughoutthe greater portion of the tube. This shaft has advantages as st-atedand may be produced upon the machine as shown in Fig. 15 by modifyingthe form of the mandrel as shown in Fig. 20. The-face of the dieremaining the same as in Fig. 15, the mandrel is hollowed out orconcaved at 101 near the point of the mandrel so that as the ballsapproach yand -leave their points of minimum diameter of the tube therewill be a clearance between the mandrel and balls increased over suchclearance during the major portion of the length of the shaft and`consequently the walls will be thicker in that region, the thickness ofthe wall tapering ofi' from the maximum thickness at the waist orminimum diameter of the tube, in both directions.

The tube thus formed may be finished upon along mandrel and with a dieas shown in Fig. 21, wherein is indicated the mandrel section 102tapering so as to conform to the desired interior of the part 110 of thegolf club shaft, and screwed into the end of the mandrel 102 is areversely tapered plug 103 corresponding to the parts 98 and 99 of theclub shaft. This long mandrel and plug being secured together and to thetube holding chuckas shown and described in connection with Figs. 17 and18. In rolling the shaft down on the mandrel the balls are shiftedalways toward the right during the tube forming operation in the samemanner as in Figs. 2 and 6. The balls first pass along the inclined diesurface 104 in rolling the long taper 110 and then pass along thesubstantially cylindrical die surface 105 whereby increased clearancebetween the balls and the mandrel to accommodate the thickening of thetube wall is provided. The lballs then pass along the reversely inclinedsurface 106 of the dle during which the reversely tapered portion 98 isrolled and then, entering upon the cylindrical die face 107 thecylindrical portion 99 of the golf shaft is rolled. Y

It will be observed from the foregoing that by suitably shaping andproportioning the die and the mandrel any desired amount and directionof taper of a tube may be obtained at any desired portion of its lengthand this with regard to either or both t-he diameter of the tube andthickness of its wall. l

The advantage of employing a device with an arrangement landconstruction of mandrel as shown in Figs. 2, 15 and other figures andthen finishing upon'a machine having a long mandrel like Figs. 6, I7 andothers is that a larger reduct-ion per draw may be accomplished on theformer while with the latter the characteristics of the tube areimproved as before explained. Where, however, the characteristics ofthetube as produced by the former are not objectionable in the use'towhich they are to be put, the tube may be completed on the formermachine and the finishing on the lat'- ter machine be dispensed with.Also if conditions are such that the larger reduction afforded by thefirst machine is not desirable the entire tapering operation upon theltube may be carried out upon the latter machine.

While the invention `has been described in what is considered its bestapplication it may have other embodiments without departing from itsspirit and is not therefore' limited to the structures shown in thedrawlngs.

What I claim is 1. Apparatus for forming tubes of varying diametercomprising in combination a drawhead, a die through which the tube isdrawn having an orifice of variable diameter and a mandrel extendingwithin the orifice and adapted to support the tube as it is drawnthrough the orifice, means for relatively moving said die and drawhead,means for varying the diameter of the mandrel at the drawing section andmeans for varying the diamter of the die in predetermined relation tothe relative movement of the said die and drawhead.

2. Apparatus for forming tubes of 'varyf l ing diameter comprising in'combination al drawhead, a die through which the tube is drawn havingan orifice of variable diameter and a mandrel extending within theorifice and adapted to support the tube as it isdrawn through theorifice, means forrelatively mov-- ing said die and drawhead, means vforvarying the diameter of the mandrel at the drawing section, means forvarying the diameter` of the die in predetermined relation to therelative movement of the said die and drawhead, and means formaintaining said mandrel in operative relation to said die.

3. Apparatus for forming tubes of vary'- ing diameter comprising incombination a drawhead, a die through which the tube is drawn having anorifice of variable diameter* and a mandrel extending within the orificeand adapted to support the tube as it is drawn through the orifice,means for relatively moving said die'and drawhead and means for varyingthe diameter ofthe die in predetermined-relation to the relativemovement of the'saidl die and drawhead, and a common means for operatingsaid mandrel' and die.

4. Apparatus for forming tubes of-varying diameter comprising incombination a drawhead, a die through which the tube -is drawn having anorifice of variable diameter and a mandrel extending within the, orificeand adapted to sup ort the tube as it is drawn through the ori ce, meansfor relatively moving said die and drawhead and means for varying theldiameter of the die in predetermined relation .to the relative movementof the said die `and drawhead, and common means forincreasin anddecreasing thevdiameter'of the die and for operating the mandrel:

5. Apparatus for forming tubes of varying diameter comprisin incombination a drawhead, a die .throug which the tube is drawn having'anorifice of variable diameter and a mandrel extending within the orificeand adapted to support the tube as it is drawn through the orifice,means for relatively moving said die and drawhead and means for varyingthe diameter of the die in predetermined relation to `the relativemovement of the said die and drawhead and a common means for relativelymoving the drawhead Aand die, varying the diameter of the die orificethrough which the tube is'drawn and moving "the mandrel in o erativ'erelation to the die.

6. Apparatus or forming tubes of varying` diameter'com risin lincombination a drawhead, a die. t roug which the tube is drawn having anorifice of-variable diameter and a mandrel ,extending within the orificeand adapted to support`the tube as it is drawn throu h the orifice, theworking members of said lie being rotating bodies, means for varying thediameter of the mandrel at the drawin section and means for relativelyrotating t e die and tube being drawn.

- 7. Apparatus for forming tubes of varying diameter comprising incombination a drawhead, a die through which the tube is drawn having anorifice of variable diameter, a -mandrel extending within the4 Vorificeand adapted'to support the tube as it is drawn through the ori ce, the.working members of said die being rotating bodies, means for relativelyrotatingl the die and tube being drawn and a carriage for said rotatingbodies, said carriage freely rotating under the action of said bodies. v

u 8. Apparatus 'for forming tubes of varying diameter comprising incombination a draw- -head,-a die through which the tube is drawn havinganoriice ofvvariable diameter, a mandrel extending within said orice andadapted to support the tube as it is drawn throu h the orifice, theworking members of said ie \being rotating bodies, means for relativelyrotating the die and tube being drawn, a carriage for said rotatingbodies, said carria e freely rotating under the action of sald bodies,and meansfor'causing relative movement'of said carriage and die to shiftthe said bodies axially of the tube with relation to said die. d

9. 'Apparatus for forming reversely tapered tube comprising incombination a drawhead, a die having an orifice of variable diameter, amandrel extending `within said orifice and adapted to support the tubebeing drawn and means for alternately decreasing and increasingthe'diameter of said orifice in predetermined relation to the positionof the l die with relation to the drawhead.

10. Apparatus for `forming reversely tapered tube of variable wallthickness, comprising in combination a drawhead a die having an orificeof variable diameter, a mandrel extending within the 'orificeand adaptedto support the tube being drawn and means for alternately decreasing andincreasing the diameter of said orifice and varying the clearance betwensaid mandrel and die at the drawing section, iny predetermined relationto the lposzion of the die with relation to the draw- 11. Apparatus forforming tubes of varying diameter comprising in combination a drawhead,a die through which the tube is drawn having an orifice of variablediameter ing within the orifice and adapted to support the tube as it isdrawn through the means `for relatively moving said die an drawhead,means for varying the diameter of the mandrel at the drawing section inpredetermined relation to the relative movement of said die anddrawhead.

12. Apparatus for forming tubes of varying diameter. comprising incombination aydrawhead, a die through which the tube is drawn having anorifice of variable diameter and a mandrel of variable diameter extending diameter comprising in combination a drawhead, a die through whichthe tube is drawn having an orifice of variable diameter and a mandrelof variable diameter extending within the orifice and adapted to supportthe tube as it is drawn through the orifice, means for relatively movingsaid die and drawhead, means for 4varying the diameter of and a mandrelof variable diameter extendorifice the mandrel at the drawing section in'predetermined relation to the diameter of the die,

the diameter of the mandrel at the drawing section decreasing as thediameter of the orifce decreases.

14. Apparatus for forming tubes of varying diameters comprising incombination a drawhead, a die' through which the tube is drawn having anorifice of variable diameter, a mandrel of variable diameter extendingwithin the orifice and adapted to support the tube as it is drawnthrough the orifice, means for relatively moving said die and drawhead,means for varying the diameter of the mandrel at the drawing section,and means for varying the diameter of the die, the diameter of themandrel at the drawing section and the diameter of the die being variedin predetermined relation to each other and to the lrelative movement ofthe die and drawhead.

In testimony whereof I have signed this specification this fourteenthday of June,

LOUIS H. BRINKMAN.

